The decision by U.S. District Judge John I. Kane reverses a 2008 decision by the U.S. Fish and Wildlife Service to continue to protect the mouse in Colorado but not in Wyoming.

Kane’s decision returns Wyoming to 1998 status, when the jumping mouse was first protected as a threatened species in both Wyoming and Colorado.

Wyoming Gov. Matt Mead is disappointed in the ruling and will review it, he said Thursday through his press secretary, Renny MacKay.

Five local and national conservation organizations filed the legal challenge to the 2008 decision by the Fish and Wildlife Service to use a “Significant Portion of the Range” policy to delist the mouse in Wyoming but not in Colorado. This policy, which was rescinded in May, allowed the federal agency to apply the Endangered Species Act only to portions of a species’ range instead of to all places where it is found.

Representatives of the conservation organizations were pleased with the decision.

“This is a great day for Wyoming wildlife. Restoring protection for the Preble’s meadow jumping mouse will benefit the dozens of other types of wildlife that rely on the streamside habitats of the High Plains for their survival,” Erik Molvar, wildlife biologist with Biodiversity Conservation Alliance of Laramie, said in a release.

“Given the precarious state of the jumping mouse in Colorado, Wyoming populations represent its best chance to escape extinction, and from the scientific perspective, stripping protections from the Wyoming populations made no sense at all,” Molvar said.

The Wyoming Stock Growers Association, the Wyoming Farm Bureau and the Wyoming attorney general’s office had intervened in the lawsuit in favor of keeping the mouse delisted in Wyoming.

Representatives of the organizations said Thursday that they were unsure what the impact of the ruling will be.

“It takes us back to protecting agricultural practices that were in place in 1998,” said Jim Magagna, the vice president of the Wyoming Stock Growers Association.

If ranchers introduced any new practices since 1998, they would have to be looked at to see if they had any impact on the Preble’s mouse.

Ranching has evolved since 1998, he said, and there could be changes in the operation of irrigation systems and grazing management practices.

“I’m not saying anybody is affected. We don’t know at this time,” Magagna said.

Landowners in that area who leased land for wind or oil and gas development could be more seriously affected than agriculture, he said.

“We’re looking at the decision to see if an appeal or any other legal action would be appropriate,” Magagna said.

Ken Hamilton, executive director of the Wyoming Farm Bureau, said he is disappointed in the ruling.

“I don’t think we were in danger of having the mouse go extinct up here,” Hamilton said. He noted that surveys of the Wyoming mouse population disclosed more numbers than expected.

The mouse is found only along stream banks in the Front Range foothills and plains of southern Wyoming and Colorado.

“Animals don’t recognize state borders,” Josh Pollock, conservation director at the Center for Native Ecosystems, said in a release. He added that stripping protection for an endangered species based on a “political boundary” was always a bad idea.

Scott Detamore of Mountain States Legal Foundation in Denver, who represented the Wyoming Farm Bureau, said he presumes the Wyoming Farm Bureau and Wyoming Stock Growers Association will participate in the new rule to be adopted by the Fish and Wildlife Service.

Detamore said he objected to tossing out the Wyoming delisting rule before the Fish and Wildlife Service adopts a new rule. But the judge ruled otherwise.

The federal agency also has pending delisting petitions filed by Wyoming and another group, Detamore said.

According to the Fish and Wildlife website, the agency documented distribution of the mouse in 10 Colorado counties and in Albany, Laramie, Platte, Goshen and Converse counties in Wyoming.

The Colorado portion of the area has undergone rapid residential commercial and industrial designation that has harmed the mouse’s habitat.